MONTPELIER — Three Vermont ski areas at least partially located in the Green Mountain National Forest could expand their summer recreational activities by taking part in a new national program designed to promote year-round recreation activities on the federal land.

Bromley, Mount Snow and Sugarbush, as well as four alpine resorts and two Nordic resorts in New Hampshire, are eligible to expand their summer activities as part of the new directives associated with the Ski Area Recreational Opportunity Enhancement Act of 2011, said Susan Mathison, the Forest Service’s Eastern Region winter sports program manager.

It’s unclear how the Vermont resorts will take advantage of the new rules because, at Bromley and Mount Snow, many of the activities being encouraged by the Forest Service area already taking place on private land controlled by the resorts. Still, the opportunity is welcome.

“Anything that we can do to encourage people to look at these resorts as a year-round designation is extremely important and then being flexible about the use of their land during the summer months just rounds out our offerings a bit more,” said Michael van Eyck, the marketing director at the Bromley Mountain Resort in Peru.

The new directives that took effect this week specifically prohibit on national forest land leased to ski areas activities such as golf courses, tennis courts and waterparks. Things that are specifically allowed include ropes courses, mountain bike trails and zip lines, she said.

“The important thing that came out in these directives ... is this gray area between the ropes courses category of activities and the golf course, tennis court,” Mathison said.

Proposals by the ski areas for summer activities on national forest land will be considered on a case-by-case basis. Depending on the scope of the proposal, approval could take anywhere from several months for a simple project to years for a more expansive proposal.

The goal is to “connect people to the natural environment,” Mathison said.

Attitash Marketing Director Thomas Prindle said that mountain already offers things like a zip line and summer gondola and has approval to add a new zip tour attraction this summer. The new regulations are a nod to increasing economic pressures on ski areas, he said.

“As an industry, I think many ski areas understand that there’s a need to be developing year-round revenue, and I think the Forest Service understands there is a need for business growth for the success of the ski areas,” Prindle said.

Dave Meeker, a spokesman for the Mount Snow ski area, said only a portion of the Mount Snow resort, like Bromley, is on national forest land and many of the activities laid out by the Forest Service can be done there on private land, but the resort is open to new ideas.

“The bottom line is we are thrilled with this new development and are excited to work with our friends in the National Forest Service if we see an opportunity to offer additional activities that would take place on public lands within the resort boundaries,” Meeker said.

The Vermont and New Hampshire resorts are among 122 ski areas across the country on almost 180,000 acres of public land. Collectively, the resorts partially on Forest Service land in Vermont and New Hampshire host more than 1.3 million visitors a year.

The Forest Service estimates that expanding ski area recreation activities nationwide will increase the number of summer visits to national forests by 600,000, create an additional 600 full- or part-time jobs and pump almost $40 million into the communities where the resorts are located.